如何清除Java中的扫描程序缓冲区？ [英] How can I clear the Scanner buffer in Java?

问题描述

我有这样的事情：

    Scanner in=new Scanner(System.in);
    int rounds = 0;
    while (rounds < 1 || rounds > 3) {
        System.out.print("How many rounds? ");
        if (in.hasNextInt()) {
            rounds = in.nextInt();
        } else {
            System.out.println("Invalid input. Please try again.");
            System.out.println();
        }
        // Clear buffer
    }
    System.out.print(rounds+" rounds.");

如何清除缓冲区？

编辑：我尝试了以下内容，但由于某些原因它无效：

I tried the following, but it does not work for some reason:

while(in.hasNext())
    in.next();

推荐答案

您无法明确清除扫描仪的缓冲区。在内部，它可能会在读取令牌后清除缓冲区，但这是在porgrammers的范围之外的实现细节。

You can't explicitly clear Scanner's buffer. Internally, it may clear the buffer after a token is read, but that's an implementation detail outside of the porgrammers' reach.

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